Pretreatment for low and non-porous media for inkjet printing

Abstract

This invention pertains to inkjet printing on non-porous or low porous media and to a pretreatment solution for the non-porous or low porous media that allows high quality printing thereon. The preferred digitally printed inks are disperse dye or pigmented inks.

1 . A method of digitally printing a non-porous or low porous media comprising:
 (a) pretreating the non-porous or low porous media with a pretreatment solution comprising an aqueous multivalent cationic salt solution and a surfactant   (b) optionally, drying the pretreated low porous media,   (c) digitally printing the dried, pretreated non-porous or low porous media with a disperse dye or pigmented ink jet ink,   (d) where the pretreatment solution has substantially no organic species other than the surfactant and the surface tension of the pretreatment solution is about 15 dynes/cm to about 33 dynes/cm.   
   
   
       2 . The method of  claim 1 , wherein the multivalent cation is selected from one or more of the group of multivalent cations of elements Mg, Ca, Sr, Ba, Sc, Y, La, Ti, Zr, V, Cr, Mn, Fe, Ru, Co, Rh, Ni, Pd, Pt, Cu, Au, Zn, Al, Ga, In, Sb, Bi, Ge, Sn and Pb. 
   
   
       3 . The method of  claim 1 , wherein the multivalent cation is calcium. 
   
   
       4 . The method of  claim 3 , wherein the pretreatment solution comprises a solution of a multivalent cationic salt in water, wherein the multivalent cationic salt is selected from the group consisting of calcium chloride, calcium chloride hydrate and mixtures thereof. 
   
   
       5 . The method of  claim 1 , wherein the pretreatment solutions comprises a solution of multivalent cation solution of about 5 wt % to about 70 wt % multivalent cation weighed as the total weight of the salt added to the solution. 
   
   
       6 . The method of  claim 1 , wherein the surface tension of the pretreatment solution is about 18 dynes/cm to about 30 dynes/cm. 
   
   
       7 . The method of  claim 1 , wherein the pretreatment solution comprises a solution of surfactant of about 0.1 wt % to about 10 wt % surfactant weighed as the total weight of the surfactant solution added to the solution. 
   
   
       8 . The method of  claim 1 , wherein the pretreatment solution comprises a solution of surfactant of about 0.25 wt % to about 8 wt % surfactant. 
   
   
       9 . The method of  claim 1 , wherein the pretreatment solution comprises a solution of surfactant of about 0.5 wt % to about 5 wt % surfactant. 
   
   
       10 . The method of  claim 1 , wherein the pretreatment solution comprises a solution of surfactant selected from the group consisting of fluorosurfactants, siloxane surfactants, and mixtures thereof. 
   
   
       11 . The method of  claim 1 , wherein the pretreatment solution is substantially free of other added organic components. 
   
   
       12 . The method of  claim 1 , wherein the non-porous or low porous media is colored, and the white pigmented inkjet ink is printed onto the colored non-porous or low porous media as a background for an image. 
   
   
       13 . The method of  claim 1 , wherein the non-porous or low porous media is printed with a white pigmented inkjet ink. 
   
   
       14 . The method of  claim 1 , wherein the non-porous or low porous media is printed with a pigmented inkjet ink set comprising at least two differently colored pigmented inkjet inks. 
   
   
       15 . The method of  claim 14 , wherein at least one of the pigmented inkjet inks is white. 
   
   
       16 . The method of  claim 14 , wherein the inkjet ink set comprises at least three differently colored pigmented inkjet inks, wherein at least one is a cyan pigmented inkjet ink, at least one is a magenta pigmented inkjet ink, and at least one is a yellow pigmented inkjet ink. 
   
   
       17 . The method of  claim 15  or  claim 16 , wherein the inkjet
 ink set further comprises a black pigmented inkjet ink.   
   
   
       18 . The method of  claim 14 , wherein the pigmented inkjet ink comprises an anionically stabilized pigment in an aqueous vehicle. 
   
   
       19 . The method of  claim 14 , wherein the pigmented inkjet individually comprise, a polymeric binder. 
   
   
       20 . The method of  claim 19 , wherein the polymeric binder comprises a crosslinked polyurethane.